As a watercolor landscape sketch in color teaching, it is an effective method to help students know and understand the basic laws of composition, modeling, color and aesthetics. Its main purpose is to understand watercolor painting, a kind of painting with rich techniques, by observing the objective scenery, while studying the basic laws of painting, to consciously exert its techniques and performance characteristics, to establish its own aesthetic consciousness, to explore its own artistic expression (watercolor language) and to express its own artistic personality.

Through years of watercolor landscape painting and teaching practice, I want to talk about watercolor landscape painting from three aspects: observation, expression and emotion. These three aspects are important links in watercolor landscape painting, and they are closely linked to form a complete whole. Observation is the first step in watercolor landscape painting. In this link, we must first solve the problem of how to observe. Watercolor landscape sketch, as an eye art, is to regard complex and changeable natural scenery as a painting. Therefore, we should have the ability to look at the overall situation from a local perspective, grasp the initiative as much as possible, establish the overall consciousness of painting, and be faithful to nature. Secondly, we should be good at discovering, and we should find pictures in a world rich in natural things. In observation, starting with the structure and shape of natural objects, we can find the composition rules of points, lines and surfaces. For example, the spatial composition of buildings, the line-plane relationship between branches and leaves of trees, the shape composition and color composition of heaven, earth and things, from which we can find the painting space and picture composition we require, and finally form a whole picture scene in our own mind. This kind of picture is hazy and uncertain, with attractive aesthetic feeling, which makes the painter have the desire and passion to express. The observation of natural images in landscape sketch should emphasize the memory and grasp of instantaneous beauty, especially the memory and grasp of light, shadow and color changes. These are the two fastest and biggest factors in sketch, and the biggest change in time is sooner or later. Therefore, it is also the most difficult to freeze light, shadow and color moments in observation. It depends on the brain's ability to remember instantaneous objects, the painter's mastery of spatial structure, light and shadow perspective, light and color principle, and the painter's proficiency in performance technology (technique).

Performance is the second link of watercolor landscape painting. In order to show the picture in your mind, you must adopt certain expression techniques. Watercolor landscape sketch, as a color sketch, can not be separated from the principles of color and materials science, and can not be separated from expression techniques. Sketchers must first decompose and study the color components of the natural images they describe. Contrast and analyze the characteristics and different functions of each color, find out the color contrast, light and shade contrast, complementary color contrast, saturation contrast, area contrast and basic tone of the natural object to be described, and establish various tone sequences. Among them, the hue order includes hue, lightness, purity and the composition of specific hue, which controls the change and unified order of each color zone. In this process, the painter is mainly required to give full play to the freedom of subjective characteristics, so that the color relationship of the picture presents a higher or more beautiful realm. Material is the basis of color expression, and different materials and tools will produce different techniques. The tool materials used in watercolor landscape painting have relatively special properties, which are different from those used in gouache and oil painting. We must have a comprehensive understanding and mastery of the performance of drawing paper, pigments, brushes, water-assisted materials and tools, find out their characteristics and advantages, and overcome the limitations and weaknesses of materials and tools, so as to fully show what we see. According to different feelings, it is the key to choose appropriate expression methods and skills and determine the basic order and steps of expression. The procedure and steps of watercolor painting are the key to the success or failure of the work. Therefore, the procedure of watercolor painting should be perfectly combined with the procedure of landscape painting, and appropriate adjustments should be made for specific natural images, so as to use the envisaged methods and steps to express natural images stably, accurately and quickly. In the specific performance techniques, we should pay attention to the treatment of brush strokes and body edge lines, the superposition of color levels, the combination and infiltration of brush strokes and wet colors, and the texture between pen and paper, which are similar to the color changes and texture characteristics of the performance object. Simple and convenient methods are often used to express the main characteristics and charm of natural images. At the same time, in the performance, we should emphasize the combination of subjective expression and objective reproduction, with objective reproduction as the main factor and subjective expression as the supplement. Sketch works that simply reproduce various relationships can hardly reach the realm of artistic expression.

In a sense, watercolor landscape painting is also the expression and exchange of emotions, and it is the third link of watercolor landscape painting. The emotion mentioned here refers to aesthetic emotion, which is an artistic form or expression of the painter's feelings about the objective world and expresses his feelings, which is also the ultimate goal of watercolor landscape painting. In the process of sketching, emotion originates from natural images, accumulates in the painter's chest, flows in his pen and condenses on watercolor paper. Therefore, watercolor landscape painting is actually a writing process from beginning to end, and brushwork is the most important language vocabulary to convey emotion, which constitutes the charm of sketch works. The completion of a landscape sketch is the product of the painter's emotional input and labor. It requires the painter to have a whole consciousness and real feelings while painting in the face of nature, so that sketch can become the painter's sincere emotion. Constable's innocence, Turner's boldness and strangeness, Van Gogh's beating fanaticism, Connor's quietness and gentleness, and Impressionism's enthusiasm and unrestrained all show the painter's emotional connotation of nature. The painter's aesthetic emotion determines the final artistic taste and style of sketch works. In watercolor landscape painting, emotion runs through observation and expression, and runs through the whole painting process.

Emotion comes from observation and also affects the painter's observation. It determines the painter's performance and is also subject to the painter's performance.